Variable flow pump

Abstract

Variable flow pump comprising at least a piston (1) associated with a chamber (2), said piston (1) cooperating with a surface (3) driven in a constant displacement reciprocating movement, characterized in that the piston (1) is free of any continuous mechanical connection with said surface (3); and wherein said chamber (2) is associated with a flow regulating system (9) placed upstream, and wherein it is equipped with a clack valve (7) on the feed and with a clack valve (8) on the delivery; said regulating system (9) being fed by a booster pump (10).

We claim: 
     
       1. A variable flow pump comprising means defining a chamber; a piston movable in said chamber;   means including a surface for reciprocating said piston with a constant displacement to vary the size of said chamber, said reciprocating means being free of any continuous mechanical connection with said piston;   means including a check valve for feeding fuel to be pumped to said chamber; and   means including another check valve for delivering pumped fluid from said chamber,   wherein said feeding means includes booster pump means for pressurizing fluid being fed to said chamber and pressure regulating means fluidically positioned in a duct between said booster pump means and said chamber for regulating the pressure of fluid reaching said chamber, said pressure regulating means comprising: (a) distributor valve means movable between a first position for closing said duct and a second position for opening said duct,   (b) a pressure limiter in said duct between said booster pump and said distributor valve means, and   (c) control means for variably controlling a control time of said distributor valve means for movement between said first and second positions for each rotation of said reciprocating means, whereby the flow of fluid through said duct is controlled by the time said distributer valve means is in said second, open position.     
     
     
       2. The variable flow pump of claim 1 wherein said chamber is defined in part by an upper face of said piston. 
     
     
       3. Variable flow pump according to claim 1 wherein the surface is the upper part of a push rod having a lower face engaging with a cam. 
     
     
       4. Variable flow pump according to claim 3, wherein the push rod slides in a guide, including a spring for maintaining the push rod in contact with the cam.